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Context-aware systems are fundamental for making the use of computing devices intuitive. These systems respond to their environments to facilitate seamless interactions between the users and their computing devices, and to make these devices less intrusive. Although it is more than a decade since context-aware systems were introduced, context is still not well understood within a context-awareness research community. Although there are numerous definitions of context, these definitions refer to context as an input or as a derivable. The majority of researchers believe any input that makes a context-aware system to accomplish its task is a context. In the contrast, there is handful of researchers who believe context is derived from more than one inputs. This paper aims to provide a clear meaning of context and consequently to resolve the differences between researchers regarding context. In particular, this paper answers the most fundamental, but yet the most avoided, question; what is context? [ABSTRACT FROM AUTHOR]

Increasing the transformer ratio of wakefield accelerating systems improves the viability of present novel accelerating schemes. The use of asymmetric bunches to improve the transformer ratio of beam based plasma systems has been proposed for some time[1, 2] but suffered from lack appropriate beam creation systems. Recently these impediments have been overcome [3, 4] and the ability now exists to create bunches with current profiles shaped to overcome the symmetric beam limit of R ≤ 2. We present here work towards experiments designed to measure the transformer ratio of such beams, including theoretical models and simulations using VORPAL (a 3D capable PIC code) [5]. Specifically we discuss projects to be carried out in the quasi-nonlinear regime [6] at the UCLA Neptune Laboratory and the Accelerator Test Facility at Brookhaven National Lab. [ABSTRACT FROM AUTHOR]